Use the %run hook function for running binaries.

doc/es.1

@@ -2550,6 +2550,15 @@ to the name of a file which contains the output of running
 the command
 .IR input .
 .TP
+.Cr "%run \fIprogram argv0 args ...\fP"
+Run the named program, which is not searched for in
+.Cr $path ,
+with the argument vector set to the remaining arguments.
+This builtin can be used to set
+.Cr argv[0]
+(by convention, the name of the program)
+to something other than file name.
+.TP
 .Cr "%seq \fIcmd ...\fP"
 Runs the commands, in order.
 .TP
@@ -2614,15 +2623,6 @@ rather than
 .Cr "%newfd"
 Returns a file descriptor that the shell thinks is not currently in use.
 .TP
-.Cr "%run \fIprogram argv0 args ...\fP"
-Run the named program, which is not searched for in
-.Cr $path ,
-with the argument vector set to the remaining arguments.
-This builtin can be used to set
-.Cr argv[0]
-(by convention, the name of the program)
-to something other than file name.
-.TP
 .Cr "%split \fIseparator \fR[\fPargs ...\fR]"
 Splits its arguments into separate strings at every occurrence
 of any of the characters in the string

es.h

@@ -150,7 +150,6 @@ extern Binding *reversebindings(Binding *binding);
 /* eval.c */
 
 extern Binding *bindargs(Tree *params, List *args, Binding *binding);
-extern List *forkexec(char *file, List *list, Boolean inchild);
 extern List *walk(Tree *tree, Binding *binding, int flags);
 extern List *eval(List *list, Binding *binding, int flags);
 extern List *eval1(Term *term, int flags);

eval.c

@@ -4,47 +4,6 @@
 
 unsigned long evaldepth = 0, maxevaldepth = MAXmaxevaldepth;
 
-static Noreturn failexec(char *file, List *args) {
-	List *fn;
-	assert(gcisblocked());
-	fn = varlookup("fn-%exec-failure", NULL);
-	if (fn != NULL) {
-		int olderror = errno;
-		Ref(List *, list, append(fn, mklist(mkstr(file), args)));
-		RefAdd(file);
-		gcenable();
-		RefRemove(file);
-		eval(list, NULL, 0);
-		RefEnd(list);
-		errno = olderror;
-	}
-	eprint("%s: %s\n", file, esstrerror(errno));
-	esexit(1);
-}
-
-/* forkexec -- fork (if necessary) and exec */
-extern List *forkexec(char *file, List *list, Boolean inchild) {
-	int pid, status;
-	Vector *env;
-	gcdisable();
-	env = mkenv();
-	pid = efork(!inchild, FALSE);
-	if (pid == 0) {
-		execve(file, vectorize(list)->vector, env->vector);
-		failexec(file, list);
-	}
-	gcenable();
-	status = ewaitfor(pid);
-	if ((status & 0xff) == 0) {
-		sigint_newline = FALSE;
-		SIGCHK();
-		sigint_newline = TRUE;
-	} else
-		SIGCHK();
-	printstatus(0, status);
-	return mklist(mkterm(mkstatus(status), NULL), NULL);
-}
-
 /* assign -- bind a list of values to a list of variables */
 static List *assign(Tree *varform, Tree *valueform0, Binding *binding0) {
 	Ref(List *, result, NULL);
@@ -449,22 +408,27 @@ extern List *eval(List *list0, Binding *binding0, int flags) {
 		char *error = checkexecutable(name);
 		if (error != NULL)
 			fail("$&whatis", "%s: %s", name, error);
+		gcdisable();
 		if (funcname != NULL) {
 			Term *fn = mkstr(funcname);
 			list = mklist(fn, list->next);
+			funcname = NULL;
 		}
-		list = forkexec(name, list, flags & eval_inchild);
+		list = mklist(mkstr("%run"), mklist(mkstr(name), list));
+		gcenable();
 		RefPop(name);
-		goto done;
+		goto restart;
 	}
 	RefEnd(name);
 
 	fn = pathsearch(list->term);
 	if (fn != NULL && fn->next == NULL
 	    && (cp = getclosure(fn->term)) == NULL) {
 		char *name = getstr(fn->term);
-		list = forkexec(name, list, flags & eval_inchild);
-		goto done;
+		gcdisable();
+		list = mklist(mkstr("%run"), mklist(mkstr(name), list));
+		gcenable();
+		goto restart;
 	}
 
 	if (fn != NULL)

prim-sys.c

@@ -60,6 +60,47 @@ PRIM(fork) {
 	return mklist(mkstr(mkstatus(status)), NULL);
 }
 
+static Noreturn failexec(char *file, List *args) {
+	List *fn;
+	assert(gcisblocked());
+	fn = varlookup("fn-%exec-failure", NULL);
+	if (fn != NULL) {
+		int olderror = errno;
+		Ref(List *, list, append(fn, mklist(mkstr(file), args)));
+		RefAdd(file);
+		gcenable();
+		RefRemove(file);
+		eval(list, NULL, 0);
+		RefEnd(list);
+		errno = olderror;
+	}
+	eprint("%s: %s\n", file, esstrerror(errno));
+	esexit(1);
+}
+
+/* forkexec -- fork (if necessary) and exec */
+static List *forkexec(char *file, List *list, Boolean inchild) {
+	int pid, status;
+	Vector *env;
+	gcdisable();
+	env = mkenv();
+	pid = efork(!inchild, FALSE);
+	if (pid == 0) {
+		execve(file, vectorize(list)->vector, env->vector);
+		failexec(file, list);
+	}
+	gcenable();
+	status = ewaitfor(pid);
+	if ((status & 0xff) == 0) {
+		sigint_newline = FALSE;
+		SIGCHK();
+		sigint_newline = TRUE;
+	} else
+		SIGCHK();
+	printstatus(0, status);
+	return mklist(mkterm(mkstatus(status), NULL), NULL);
+}
+
 PRIM(run) {
 	char *file;
 	if (list == NULL)